RE the in line attenuation, I have decided that I may have over thought this situation and no longer am considering the use of them.I'm assuming the reason for asking about the inline attenuators is that maybe you feel your Schiit Sys volume control is coming on too fast still down low?
This could be a possibility if Schiit use a 10kohm pot, but a "linear one" and not a "logarithmic one", then it did only cost $49.
The Lightspeed is made so it behaves like a logarithmic pot, so it's volume will come on slow and build till you get to around 2o'clock after which it's volume increases far more rapidly.
Cheers George